It is a known fact that the manufacturers of casual-fashion clothing made of denim materials in order to follow the trend of the market, treat the articles of clothing so as to give them a worn-out aspect.
In order to give the article of clothing said worn-out aspect, a washing operation is performed during which the article of clothing is treated with proper enzymes or with pumice powder, thereby producing the discoloring of the cloth and the worn out aspect previously mentioned. Sometimes it is also required that said articles of clothing present a worn out aspect which is localized only over particular areas. This is obtained by concentrating in the concerned areas a particularly strong discoloring operation through supplementary treatments.
One of the known methods used to perform such treatment consists in a very energetic manual brushing of the areas of the article of clothing where the discoloring is to be concentrated, thereby obtaining what in the technical jargon of this industrial sector is called "sanded effect". The inconveniences of such method of operation are rather obvious, the most evident being the length of time required by this operation and the ensuing high labor costs. Moreover, since this process must be performed manually, and depends exclusively on the operator's skill, it does not guarantee any continuity or reproduction of the same quality in the finished product.
Another known method consists in performing manually a localized sanding process by blasting the article of clothing with a mixture of air and sand. This method presents the same inconveniences presented by the before-described method with the addition that is it also highly polluting both for the environment and for persons involved in the process, so that it requires suitably equipped spaces for it be carried out.